Cori Cycle

The Cori Cycle operates during exercise, when aerobic metabolism in muscle cannot keep up with energy needs.

For a brief burst of ATP utilization, muscle cells utilize ~P stored as phosphocreatine. For more extended exercise, ATP is mainly provided by Glycolysis.

Lactate, produced from pyruvate, passes via the blood to the liver where it is converted to glucose. The glucose may travel back to the muscle to fuel Glycolysis.

The Cori Cycle costs 6 P in liver for every 2P made available in muscle. The net cost is 4 P Although costly in terms of "high energy" bonds, the Cori Cycle allows the organism to accommodate to large fluctuations in energy needs of skeletal muscle between rest and exercise.

Cholesterol synthesis:

Hydroxymethylglutaryl-coenzyme A (HMG-CoA) is the precursor for cholesterol synthesis. 

HMG-CoA is also an intermediate on the pathway for synthesis of ketone bodies from acetyl-CoA. The enzymes for ketone body production are located in the mitochondrial matrix. HMG-CoA destined for cholesterol synthesis is made by equivalent, but different, enzymes in the cytosol.

HMG-CoA is formed by condensation of acetyl-CoA and acetoacetyl-CoA, catalyzed by HMG-CoA Synthase.

HMG-CoA Reductase, the rate-determining step on the pathway for synthesis of cholesterol.

 Polar (Uncharged)

 Mnemonic: "Santa’s Team Never Quit Trying Cookies" (S, T, N, Q, T, C)

Non-Polar (Hydrophobic)

Mnemonic: "Grandma Always Visits London In May For Perfect Weather" (G, A, V, L, I, M, F, P, W)

Protein electrophoresis is a laboratory technique used to separate proteins based on their size, charge, or other physical properties. It plays a vital role in diagnosing and monitoring various diseases, especially those involving abnormal protein production or structure.

Types of Protein Electrophoresis

1. SPE (Serum Protein Electrophoresis)

• Principle: Separation of serum proteins based on their charge.

• Major Fractions:

  • Albumin

  • Alpha-1 globulin

  • Alpha-2 globulin

  • Beta globulin

  • Gamma globulin

• Clinical Applications:

  • Multiple Myeloma: Detects monoclonal spike (M-protein) in gamma region.

  • Chronic Infections: Polyclonal increase in gamma globulins.

  • Nephrotic Syndrome: Decreased albumin, increased alpha-2 globulin.

  • Liver Disease: Altered albumin and beta-gamma bridging.

2. Hemoglobin Electrophoresis

• Principle: Separation of hemoglobin variants based on charge differences.

• Common Hemoglobins:

  • HbA, HbA₂, HbF, HbS, HbC, HbE

• Clinical Applications:

  • Thalassemia: Elevated HbA₂ or HbF levels.

  • Sickle Cell Disease: Presence of HbS.

  • Hemoglobinopathies: Differentiates variants like HbC, HbE, etc.

3. SDS-PAGE (Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis)

• Principle: Proteins are denatured and separated by molecular weight.

• SDS: Imparts uniform negative charge, eliminating charge-based separation.

• Clinical Applications:

  • Protein Purification: Identifies specific proteins in research and diagnostics.

  • Genetic Disorders: Detects abnormal or truncated proteins.

  • Muscular Dystrophies: Analyzes dystrophin protein expression.

  • Cancer Research: Studies tumor markers and oncogenic proteins.

FLUORIDE

The safe limit of fluorine is about 1PPM in water. But excess of fluoride causes Flourosis

Flourosis is more dangerous than caries. When Fluoride content is more than 2 PPM, it will cause chronic intestinal upset, gastroenteritis, loss of weight, osteosclerosis, stratification and discoloration of teeth

These can be synthesized by the body from other compounds.

The body makes these from carbohydrates and other amino acids.